If .00840 mol is the answer to this question (Suppose that 16.41 mL of 0.0512 M NaOH were required to titrate a sample of unknown acid. How many moles of NaOH were used? ) how would I answer this: Assuming that the unknown acid sample in question 1 had a mass of 0.177 g, what is the molar mass of the unknown acid?
You know the moles:
molarmass*moles=mass or
molar mass=mass/moles
So if I did .00840 mol X .177g I'll get .00148 but my quiz says that's wrong still.
.177/.00840= about 21, I think.
Thank you!
Is there any way you could help me with this one also? We will calculate the amount of acid to use in each titration. Assume that you are using 0.0512 M NaOH(aq). A good volume of NaOH(aq) to use per titration is 15 mL. From this molarity and volume, the moles of NaOH can be calculated. Since the unknown acid is monoprotic, this also equals the number of moles of acid to use. A typical molar mass for an unknown acid in this experiment is 380 g/mol. Using this molar mass, calculate the mass (in grams) of unknown acid you should use per titration. Since we have been estimating values, round your answer to two significant figures.
MolesNaOH=.015*.0512
massacid/380=above
massacid=above*380
solve for mass of acid...to two sig digits.